//7.编写程序完成strcat 的功能
#include<stdio.h>
#include<string.h>
#define N 81
int main()
{
	char c1[N] = "HELLO WORLD";
	char c2[] = "HELLO KETTY";
	int n = strlen(c1);
	int M = sizeof c2;
	for(int i = 0; i < M ;i++)
	{
		c1[n] = c2[i];
		n++;
		if(c2[i] == '\0')
			break;
	}

	puts(c1);
	return 0;
}
